const tree = {
    val: '1',
    left: {
        val: '2',
        left: {
            val: '4'
        },
        right: {
            val: '5'
        }
    },
    right: {
        val: '3',
        left: {
            val: '6'
        },
        right: {
            val: '7'
        }
    }
}

module.exports = tree